Brake actuating means



" g Y .BRAKE TACTUAING MEANS.

' Filed Augjleg- 1941!, s sheets-snaai 1 f An'oRNEY Patented May 22,1945 BRAKE ACTUATING MEANS Rudolph A. Goepfrich, south Bend, Ind.,assignmto Bendix Aviation Corporation, South Bend, Ind., a corporationof Delaware Application August 16, 1941, Serial No. 407,101 l 8 Claims.

This application'relates to friction devices and particularly tofriction'devices which are actuable by liquid.

My invention will be illustrated and described with reference to a brakeof the disk type. It will be appreciated that devices other'than brakesmight incorporate my invention and likewise that, in the field ofbrakes, there are other types of brakes which might advantageously usethe principles described and applied in this application.

There are certain desirable qualities inherent in disk brakes such assmoothness of action and extensive friction surface with consequentlower heat per unit of lining area. However, on the other side of theledger are problems which have va disk brake is the inclusion of aself-energization feature in the brake so that the torque exerted.'

by the rotating member when it is being fric-` tionally braked will tendto increase the applying force.

Use of self-energizing disk brakes may in itself i raise problems due todanger of locking and need for effective releasing means. Consequently adisk brake which is effective 'without self-energization is highlydesirable.

It is my chief object to provide a disk brake which may attain a higheffectiveness without self-energization. A higheifectiveness is-attained when the ratio of brake applying force or pressure tending tomove'the friction elements against one another to unit line pressure inthe conlziuits carrying pressure liquid is relatively hig To provide aneifective brake, I have used a. plurality of liquid containers orcylinders, each of them exerting aL brake applying force on the frictionelements in accordance withthe line pressureexisting in the liquidconduits connected to the cylinders. 'I'he total applying force orrectly proportional to thehumber of cylinders.

The use of a plurality of brake applying cylinders might beprohibitively expensive exceptvpressure for any given unit line pressureis di- (ci. iss-152) stamped cylinders welded or brazed to a formedtube. The substitution of stamped cylinders for cast cylinders effects asubstantial saving in manufacturing cost with the result that it is'possible to use a larger number of cylinders with a larger total pistonarea on which brake applying pressure is exerted.

The end result of the above is the provision of a highly effective anddependable brake which at the same time is very smooth and controllablein operation. I

The saving in manufacturing cost results not only from the substitutionof the simple stamping operation for the casting .process but also fromthe avoidanceof high machining costs. In cast iron cylinders of the typeconventionally used any bosses or nipples, for example, to accommodatethe inlet passage and bleeder screw, are cast integral with the body andthey have to Abe carefully machined. The use of stamped steel cylindersin place of cast iron cylinders makes possible a thinner cylinder wallwhich can be punched or drilled in a single operation. Cast ironcylinders do not lend themselves readily to such handling.

In handling the fittings or bosses, any machining operations which mustbe performed on them are more easily performed when the ttings are apartfrom the cylinder than when they are cast integral with it. In line withthis, an advantage is gained by forming the necessary bosses and" tubesseparately from the stamped cylinders and then welding or brazing themto the cylinders, all the parts being secured to all the cylinders in asingle operation.

Other features and advantages of my invention will become apparentduring the course of the following description in which reference is hadto the accompanying dravm'ngs.

In the drawings:

Figure 1 is an elevation showing a disk brake assembly incorporating myinvention and showing a hydraulic brake applying cylinder in section;

Figure 2 is a vertical` section taken on the line 2-2 of Figure 1;

Figure 3 is a view showing the brake vapplying means and fluid carryingmeans of Figures 1 and 2 before assembly;

Figure .4 shows the brake applying means and w fluid carrying means ofFigures 1, 2 and 3 after the fluid carrying means or tube has been bent;

Figure 5 is a close-up showing the end of the tube of Figure 4 connectedto a fitting:

Figure 6 shows a modificationv of the wheel cylfor my provision of abrake assembly which has Il inder and conduit-assembly of Figure 4, thesaid the straight tube 2|.

assembly being shown as it appears before the cylinders are welded orbrazed to the tubes and before the tube'has been bent; and

Figure '7 shows the device of Figure 6 after the tube has been bent andwhen the assembly is ready to be positioned on the brake.

In Figures 1 and 2, I have illustrated a disk brake assemblyincorporating my invention. As shown, said brake assembly includes arotatable drum I having associated therewith a rotor disk II faced withfrictional lining material, a stationary supporting member I2, andnon-rotatable axially movable disk I3. The rotatable disk Il extendsbetween the disk I3 and the supporting member I2, so that the rotationof the disk may be impeded and stopped when the axially movable disk I3is moved toward the supporting mem- :ber I2 to clamp the rotatable diskIl therebetween. A plurality of rods I are connected as by nuts I5 tothe axially movable disk I3. The rods pass through openings in thesupporting member l2 and into hydraulic cylinders I6 wherein they areconnected to pistons Il which are reciprocable in the cylinders I6.Packings I8 are provided to prevent the escape of fluid from cylindersI6 and light springs I9 are provided in each cylinder tending to movethe piston away from the supporting member. Springs 20 are compressedbetween the supporting member and the axially movable disk I3 adjacenteach rod Il in order to hold the disk I3 in brake released position.

The cylinders I 6 are formed by using the stampn ing process referred toas drawing and have the shape of cups with the bottom portion of the cupabutting the supporting member I2 and the top or open portion of the cupserving to admit the piston head when the pistons are inserted in thecylinders. I have shown a brake using three stamped cylinders. Obviouslyany number of cylinders could be utilized withoutdeparting from myinvention, but it has been found that three is a satisfactory number. Inthe brake assembly (see Figure 1) the cylinders are positioned around acircumference of the brake supporting member I2, each one approximately120 from the others.

Before the cylinders are assembled with the brake, they may be welded orbrazed to a tube 2i. The tube 2l interconnects all of the cylinders andalso serves to connect them to a source of fluid pressure. At one end ofAthe tube, a fitting 22 is provided, preferably welded or brazed Ytheend cylinders The assembly of tube and cylinders is put into a furnacehaving an atmosphere of hydrogen or the like to weld or braze the partstogether in the well known manner. After this is done, the

. tube may be bent tothe desired shape and the whole tube and cylinderassembly may be assembled With the brake in such a manner that the tubeis tangent to each of the cylinders at or near the highest point of thecylinder as it is positioned in the assembled brake. It is not necessarythat the tube bending be done after the welding process but it isdesirable. One reason being that a given amount of space in a weldingfurnace canv accommodate a larger number of tube and cylinder assemblieswhen the assemblies are in the straight or single line position. Duringthe time the cylinders are being weldedvto the tube, the fittings 22 and23 may be welded to the ends of the tube as illustrated in Figure 5.

In Figures 6 and 7, I have illustrated a modi-I iication of the tube andcylinder assembly which is probably even more satisfactory than the tubeand cylinder assembly of Figures 3 and 4. In the device of Figures 6 and'7, the ends of tubes 2Ia and 2lb are pressed into openings 24a in thesides of the cylinders I6. vFittings 22a and 23a arelikewise pressedinto openings 24h in each of After the assembly has been horizontallyformed as shown in Figure 6, it is put through a welding or brazingfurnace withthe result that the fittings, tubing and cylinders are allwelded together to form alunitary assembly. This assembly is thenassembled with the brake as shown in Figures 1 and 2.

The method of making a brake assembly disclosed in the presentapplication is claimed in to the end of the tube and at the other end ofl the tube a fitting 23 is welded or brazed. The fitting 22, which ispreferably located higher than any other portion of the tube,accommodates a bleeder screw 24 and fitting 23 is connected to a iluidconduit (not shown) which leads to a source of iluid under pressure.

Openings 25 are punched, drilled or otherwise provided in the cylindersI6, and complementary ntack Weld the cylinders to the tubebefore the nnlWelding or bracing operation.

divisional application Serial No. 545,283, led July 1'7, 1944.

Although I have described certain specific emi bodiments of my device,it will be apparent that many modifications of the said device can bemade without departing from the scope of my invention. I thereforedesire that my invention be limited not by the description or drawingsbut only by the terms of the appended claims.

I claim:`

l. Actuatlng means for a disk brake comprising a plurality of cup-shapedstampings, each having an opening in the side thereof at approximatelyits highest point, a bent tube secured to each of the cylinders andhaving a plurality of openings aligned with the openings in thecylinders, one end of said tube being higher than any other portion ofthe tube, a bleeder plug in the high end of the-tube, and an inlet ttingat the opposite end of the tube.

2. Actuating means for a disk brake comprising a plurality ofcircumferentially spaced cupshaped stampings. each having an opening inthe side thereof at approximately its highest point, a bent tube securedto each of the cylinders and having a plurality of openings aligned withthe openings in the cylinders; one end of said tube beinghigher than anyother portion of the tube, a bleeder plug in the high end of the tube,and an inlet ttingat the opposite end of the tube.

3. Actuating means for a disk brake comprising a plurality of cup-shapedstampings each having an opening -in the side thereof at approximatelyits highest point, a single bent tube secured to all of the cylindersand having a plurality of openings aligned with the openings in thecylinders, one end of said tube being higher than any other portion ofthe tube, a bleeder plug in the high end of the tube, and an inlet ttingat the opposite end of the tube.

4. Actuating means for a, disk brake comprising three circumferentiallyspaced Vcup-shaped 'stampings tubing connecting said stampings to form aunitary huid-interconnected assembly, one end of said tubing beinglocated higher than any other portion of said unitaryhuid-interconnected assembly, and a bleeder plug in the high end of saidtubing. A

5. Actuating means for a disk brake comprising three circumferentiallyspaced cup-shaped stampingvs, tubing connecting'said stampings to form aunitary fluid-interconnected assembly, a weld securing each of thestampings directly to the tubing, one end of said tubing being locatedhigher than any other portion of said unitary fluid-interconnectedassembly, and a bleeder plug in the high end of said tubing v 6.Actuating means for a disk brake comprising three circumferentiallyspaced `cup-shaped stampings, tubing consisting of a single bent tubeconnecting said stampings to form a unitaryduid-interconnected assembly,a Weld securing each of the stampings directly to the tubing, one

end of said tubing being located higher than any other portion of saidunitary huid-interconnected assembly, and a bleeder plug in the high endof said tubing. Y

7. Disk brake actuating means comprising a plurality of cup-shapedstampings, and a single bent tube interconnecting said 'stampings andlying tangent to each of them at or near the highest point of therespective stamping, one end of said tube being higher than any otherportion thereof and being provided with a bleed opening.

8. Actuating means for a, disk brake comprising a plurality ofcircumferentially spaced cupshaped stampings, each having an opening inthe side thereof at approximately its highest point, a bent tube securedto'each of the cylinders and having a, plurality of openings alignedwith the openings in the cylinders, a weld securing each of thestampings to the tube, one end of said

